<!DOCTYPE html>

<html>
    <head>
        <title></title>
        <style type="text/css">
            #tim {
                width: 200px;
                height: 200px;
                border: 1px solid black;
                margin: 0 auto;
            }
        </style>
    </head>

    <body>
        <div id = "tim" onmouseover="tim.style.background='red'" onmouseout="tim.style.background='white'">
            
        </div>
    </body>
</html>

</html>